1. Field of the Invention
The present invention relates to a two wire to four wire converter device for connecting a private telephone network to the public telephone network.
2. Description of the Prior Art
Hitherto the electrical isolation of a connecting device between a private telephone network and a public telephone network was generally in the form of a transformer, whereof one winding was connected to the private network and the other to the public network via a high capacitance capacitor arranged in series with said winding.
This known connecting device has a number of disadvantages as a result of the relatively high cost of the transformer used, the brittleness of the ferrite of this transformer and the overall dimensions of the transformer and capacitor, which must have a high capacitance as stated hereinbefore.
The present invention relates to a connecting device of the aforementioned type, whose cost and overall dimensions are significantly reduced compared with the known devices and which is no more fragile or brittle than they are.